[NFC] Internalize the REPL's LLVMContext
[NFC] Internalize the REPL's LLVMContext

There's no reason the REPL needs to generate its starting module in the
global LLVMContext. Give it a local context.

jmgc/swift,nathawes/swift,jmgc/swift,parkera/swift,jckarter/swift,gregomni/swift,parkera/swift,rudkx/swift,xwu/swift,nathawes/swift,gregomni/swift,harlanhaskins/swift,airspeedswift/swift,harlanhaskins/swift,tkremenek/swift,glessard/swift,ahoppen/swift,parkera/swift,benlangmuir/swift,allevato/swift,glessard/swift,rudkx/swift,tkremenek/swift,harlanhaskins/swift,JGiola/swift,tkremenek/swift,ahoppen/swift,xwu/swift,atrick/swift,harlanhaskins/swift,gregomni/swift,jckarter/swift,hooman/swift,parkera/swift,apple/swift,roambotics/swift,jmgc/swift,glessard/swift,jmgc/swift,CodaFi/swift,gregomni/swift,xwu/swift,airspeedswift/swift,tkremenek/swift,roambotics/swift,CodaFi/swift,harlanhaskins/swift,xwu/swift,xwu/swift,stephentyrone/swift,ahoppen/swift,glessard/swift,JGiola/swift,xwu/swift,jmgc/swift,hooman/swift,nathawes/swift,allevato/swift,stephentyrone/swift,atrick/swift,rudkx/swift,tkremenek/swift,roambotics/swift,airspeedswift/swift,airspeedswift/swift,aschwaighofer/swift,nathawes/swift,JGiola/swift,parkera/swift,nathawes/swift,apple/swift,CodaFi/swift,tkremenek/swift,aschwaighofer/swift,jckarter/swift,allevato/swift,atrick/swift,rudkx/swift,atrick/swift,CodaFi/swift,JGiola/swift,nathawes/swift,benlangmuir/swift,hooman/swift,apple/swift,parkera/swift,ahoppen/swift,ahoppen/swift,allevato/swift,aschwaighofer/swift,hooman/swift,rudkx/swift,benlangmuir/swift,harlanhaskins/swift,jckarter/swift,jckarter/swift,harlanhaskins/swift,hooman/swift,glessard/swift,CodaFi/swift,allevato/swift,aschwaighofer/swift,allevato/swift,allevato/swift,tkremenek/swift,atrick/swift,glessard/swift,jckarter/swift,stephentyrone/swift,hooman/swift,aschwaighofer/swift,roambotics/swift,jckarter/swift,aschwaighofer/swift,stephentyrone/swift,JGiola/swift,JGiola/swift,CodaFi/swift,stephentyrone/swift,jmgc/swift,stephentyrone/swift,gregomni/swift,apple/swift,benlangmuir/swift,parkera/swift,aschwaighofer/swift,xwu/swift,benlangmuir/swift,roambotics/swift,ahoppen/swift,gregomni/swift,airspeedswift/swift,hooman/swift,rudkx/swift,nathawes/swift,roambotics/swift,stephentyrone/swift,apple/swift,airspeedswift/swift,airspeedswift/swift,parkera/swift,CodaFi/swift,benlangmuir/swift,jmgc/swift,apple/swift,atrick/swift